It is known to form honeycomb structures, and the like, by thermally fusing (i.e., welding) cut pieces of thermoplastic material together to form an expandable cellular block, and then heating and pulling on the block to expand it and thereby convert it into a honeycomb structure. Although methods and apparatus are known for constructing honeycomb structures in this manner, it is desirable to improve the speed at which such honeycomb structures can be formed, and the quality of those honeycomb structures. For example, some prior methods and apparatus for forming honeycomb structures can be characterized as being too slow, or inefficiently requiring that the honeycomb structures be formed in batches, as opposed to via a continuous process. As another example of problems that can occur in the manufacture of a honeycomb structure, in some cases the welds between the pieces of thermoplastic material are not strong enough to withstand the pulling that is required to convert the expandable block into a honeycomb structure. The breakage of the welds negatively impacts the integrity of the final honeycomb structure.
In view of the foregoing, there is a need for improved methods and apparatus for forming expandable blocks and/or honeycomb structures.